Abstract
Sputter deposition of 50 nm thick NiO films on p+-n-Si and subsequent treatment in an Fe-containing electrolyte yielded highly transparent photoanodes capable of water oxidation (OER) in alkaline media (1 M KOH) with high efficiency and stability. The Fe treatment of NiO thin films enabled Si-based photoanode assemblies to obtain a current density of 10 mA/cm2 (requirement for >10% efficient devices) at 1.15 V versus RHE (reversible hydrogen electrode) under red-light (38.6 mW/cm2) irradiation. Thus, the photoanodes were harvesting ∼80 mV of free energy (voltage), which places them among the best-performing Si-based photoanodes in alkaline media. The stability was proven by chronoamperometry at 1.3 V versus RHE for 300 h. Furthermore, measurements with electrochemical quartz crystal microbalances coupled with ICP-MS showed minor corrosion under dark operation. Extrapolation of the corrosion rate showed stability for more than 2000 days of continuous operation. Therefore, protection by Fe-treated NiO films is a promising strategy to achieve highly efficient and stable photoanodes.
Original language | English |
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Pages (from-to) | 3456-3461 |
Number of pages | 6 |
Journal | Journal of Physical Chemistry Letters |
Volume | 5 |
Issue number | 20 |
DOIs | |
Publication status | Published - 16 Oct 2014 |
Keywords
- electrochemical quartz crystal microbalance
- oxygen evolution reaction (OER)
- photoelectrochemical water splitting
- stability
- thin film
ASJC Scopus subject areas
- Materials Science(all)
- Physical and Theoretical Chemistry